Arrangement for closing roll nips

ABSTRACT

A multi-roll calender ( 1 ) has one or several sets of rolls ( 2 ) attached to a frame ( 7 ) so that each set of rolls has at least three rolls. At least the first roll ( 3; 31 ) and the last roll ( 3; 32 ) have casings which can be moved toward the intermediate rolls ( 4 ). The first roll ( 3; 31 ) and the last roll ( 3; 32 ) are fixedly attached, at least one of the intermediate rolls ( 4 ) in the set of rolls is fixedly attached, and the other intermediate rolls are provided with lightening elements for lightening the auxiliary means related to the intermediate rolls. The roll nips (N) in the set of rolls ( 2 ) are closed by moving the first roll towards the intermediate rolls ( 4 ), and the roll nips between the last roll and the fixed intermediate roll included, are closed by moving the last roll towards the intermediate rolls ( 4 ).

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a U.S. national stage application of InternationalApplication No. PCT/FI03/00445, filed Jun. 5, 2003, the disclosure ofwhich is incorporated by reference, and claims priority on FinnishApplication No. 20021084, Filed Jun. 6, 2002.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSOREDRESEARCH AND DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

The invention relates to an arrangement for closing roll nips in amulti-nip calender.

In a multi-roll calender (in the following also multi-nip calender)there often are as many as 10-12 rolls, which are located in the same ora different set of rolls in the same or a different frame so that oneset of rolls always has 3-12 rolls. Each set of rolls has a first rolland a last roll, and one or more intermediate rolls between these rolls.In a set of rolls, a roll nip is always left between two adjacent rolls,in which roll nip the surface of the fibre web is profiled in a desiredway. In a multi-roll calender, the roll nip is generally formed betweena roll with an elastic surface, such as a polymer-coated roll, and aheated, smooth-surfaced steel roll or cast iron roll. For calenderingboth sides of the fibre web in the same way, the multi-roll calenderoften has a so-called reverse nip, which is a roll nip formed betweentwo similar rolls, such as, for example, between two polymer-coatedrolls. The one-sidedness of the fibre web can also be controlled sothat, instead of the reverse nip, the calender is divided into twodifferent sets of rolls. In a usual supercalender, in which the plane ofthe set of rolls is located substantially vertically in relation to thefloor plane, the uppermost and the lowermost roll are variable crownrolls with chilled surfaces, in other words rolls, in which thedeflection caused by their own weight has been compensated by internalloading elements of the roll. The intermediate rolls are alternatelyrolls with chilled surface, heated by water, and paper-or polymer-coatedrolls; nowadays, most often polymer-coated rolls. The linear pressure inroll nips grows when transferring from the upper nip to the lower nip,due to earth gravity, and the linear loads of the roll nips depend onthe specific weight of the rolls. The linear loads transverse to themachine direction of the roll nips, i.e. the linear loading profile alsooften has deflections, due to the load forces influencing the axlejournals at the ends of the intermediate rolls, caused by auxiliarymeans, such as bearing houses and steam boxes.

In the so-called Optiload multi-roll calendering (multi-nip calendering)developed by Metso Paper, Inc., the own weight of the intermediate rollshas been lightened so that the axle journals are attached to loadingarms: each intermediate roll is attached to loading arms from thebearing houses, the loading arms being again attached to the calenderframe. With the loading arms it is possible to direct roll-liftingforces of different sizes to the ends of the roll and thus to compensateto a desired extent the influence caused by the own weight of the rolland the auxiliary means, loading the roll nips and thus increasing thelinear loads of the roll nips. In this calendering method, also thedeflections caused by the auxiliary means at the ends of the rolls havebeen compensated in the linear loading profiles transverse to themachine direction of the roll nips. The intermediate rolls have furtherbeen selected so that they have almost the same specific deflectioncaused by earth gravity. In this kind of calendering method, it ispossible to use substantially the same linear pressure in all roll nips,i.e. the linear load distribution of the roll nips is uniform. Of thepresent calendering methods, this calendering method has the largestcalendering window, i.e. with this method, it is possible to calenderalmost all paper qualities with high speeds while keeping the profilingquality of the paper good.

In the so-called Optiload method disclosed above, the lowermost roll isarranged to move on guide tracks in the calender frame, and thecalendering is initiated by closing the roll nips above the lower rollby lifting the lowermost roll upwards in the plane of the intermediaterolls using hydraulic cylinders attached to the bearing houses. Theadditional load to the roll nips is brought either from above or below,for example, by loading the uppermost or lowermost roll with theadditional load.

SUMMARY OF THE INVENTION

The principal object of the invention is to eliminate the drawbacks inthe state-of-the-art technology. Thus, the object of the invention is toprovide a method for closing the roll nips in a set of rolls, in whichit is possible to replace the heavy hydraulic cylinders connected to thelower roll with a lighter arrangement. It is also the object of theinvention to provide a method, in which the control of the linear loadsof the roll nips and the control of the roll loads in a set of rollsstays good, irrespective of the changed closing method of the roll nips.

In the arrangement of the invention, the multi-roll calender (multi-nipcalender) has one set or several sets of rolls attached to one frame orseveral frames. Each set of rolls has at least three rolls, and at leastthe first roll and the last roll in the set of rolls is provided withequipment, with which their casing can be transferred in the directionof the plane of the set of rolls towards the intermediate rolls in theset of rolls. In the arrangement, the first roll and the last roll inthe set of rolls are fixedly attached, and further, at least one of theintermediate rolls in the set of rolls is fixedly attached. The otherintermediate rolls are preferably provided with equipment for lighteningthe own weight of the intermediate rolls and/or the auxiliary meansrelated to the intermediate rolls. In this case, the roll nips in theset of rolls are closed so that the roll nips of the rolls between thefirst roll and the fixedly attached intermediate roll are closed bymoving the first roll in the set of rolls in the direction of the planeparallel to the set of rolls towards the intermediate rolls, and theroll nips between the last roll and the fixedly attached intermediateroll are closed by moving the last roll in the set of rolls in thedirection of the plane parallel to the set of rolls towards theintermediate rolls.

In this application, the direction of the plane of the set of rollsrefers to the direction of the plane drawn through the centre line ofthe rolls in the set of rolls.

In the arrangement disclosed above, there is no need for heavy hydrauliccylinders for lifting the last roll in the set of rolls, i.e. often thelowermost roll as the roll nips are closed, because the first roll andthe last roll (or upper roll and lower roll, if the set of rolls is in avertical position in relation to the floor plane) are fixedly attachedto the frame or some other fixed structural element, and the roll nipsare closed by moving the casing of the first roll and the last rolltowards the intermediate rolls.

In an advantageous embodiment of the invention, the linear loaddistribution of the roll nips in the set of rolls is adjusted bybringing an additional load to the first and/or last roll in the set ofrolls, which generates the linear load to the roll nips in the set ofrolls. As distinct from the conventional multi-roll calendars, theadditional load does not influence the linear load distribution of theroll nips in a uniform or linear way, but the extent of the load in acertain roll nip depends on whether the roll nip in question is locatedbefore the fixedly attached intermediate roll or after the intermediateroll as the set of rolls is looked at from the direction of theinfluencing force. Thus, the additional load of the first roll has asubstantially smaller effect on the linear loads of the intermediaterolls between the fixedly attached intermediate roll and the last rollthan on the linear loads of the roll nips of the intermediate rollsbetween the attached intermediate roll and the first roll. Theadditional load of the last roll again has a substantially smallereffect on the linear loads of the roll nips between the fixedly attachedintermediate roll and the first roll than on the linear loads of theroll nips between the fixedly attached intermediate roll and the lastroll.

Thus, a considerable difference is achieved by the fixedly attachedintermediate roll to the linear load distributions of the roll nipslocated on different sides of the intermediate roll in question. In thiscase, the fixedly attached intermediate roll provides the considerableadvantage that there are more means than usual to adjust the linear loaddistribution of the roll nips and that more possibilities are obtainedto adjust the calendering potential of the calender, with which it ispossible to adjust, among others, the profiling result of both sides ofthe fibre web in a more exact manner than before.

The invention is next described in more detail by referring to drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a multi-roll calender seen directlytowards the end of the set of rolls as the roll nips are being closed.

FIG. 2 is a schematic view of the development of the linear loaddistribution of the set of rolls in FIG. 1 in roll nips located ondifferent sides of the fixedly attached intermediate roll, seen from thefront.

FIG. 3A is a schematic view of a multi-roll calender with two sets ofrolls in the same frame, seen directly towards the end.

FIG. 3B is a schematic view of a multi-roll calender with two sets ofrolls in two different frames, seen directly towards the end.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The main structures of the Figures and which part of the invention theFigures are meant to illustrate, are first gone through. FIG. 1illustrates the vertical multi-roll calender 1 (=multi-nip calender)arranged to the same calender frame, with five intermediate rolls 4. Ofthe intermediate rolls, the middlemost one is attached to the calenderframe 7, and the other intermediate rolls are provided with lighteningequipment for compensating their own gravity. The uppermost andlowermost roll 3 of the calender are attached to the calender frame. Inthe situation according to FIG. 1, the calendering of the fibre web W isinitiated, and the roll nips N are closed.

FIG. 2 illustrates the development of the linear load distribution ofthe roll nips N on different sides of the attached intermediate roll ina multi-roll calender of the invention, the set of rolls 2 of which issimilar to the one shown in FIG. 1. The set of rolls 2 is shown as asimplified diagram for illustrating the loads. The Figure illustratesthe linear pressure generated by the additional load in the roll nips N;Nb1, Nb2 on different sides of the intermediate roll 4; 43, and thedevelopment of the linear load distribution in the roll nips N of theset of rolls.

FIG. 3A illustrates an advantageous embodiment of the invention, inwhich the multi-roll calender has two sets of rolls 2. Both parts of theset of rolls are attached to the same calender frame. Both parts of theset of rolls have the first roll and the last roll 3 (the upper andlower roll), which are fixedly attached to the frame, and there arethree intermediate rolls 4 between them. Of the intermediate rolls, thetwo outermost ones 4; 41, 43 are attached to the loading arms and themiddlemost one is fixedly attached to the calender frame. The calenderframe and the attachment of the rolls to the frame and the loading armsare left out of FIG. 3A for simplifying the Figure. These structures aresimilar to the ones in FIG. 1.

FIG. 3B illustrates a second advantageous embodiment of the invention,in which the set of rolls has two parts of the set of rolls. Both partsof the set of rolls are similar to the ones in FIG. 3A, but they areattached to different frames. FIG. 3B has been simplified in a similarmanner as FIG. 3A.

The multi-roll calender 1 according to FIG. 1 has the upper roll 3; 31and the lower roll 3; 32, and five intermediate rolls 4; 41, 42, 43, 44,45. The upper and lower rolls are shown as a partial cross-sectionalfigure for illustrating the load equipment 31 a and 32 a inside them. Inaddition, the calender 1 includes take-off rolls 6, with which the fibreweb arriving from the previous roll is detached from the roll surfacebefore the fibre web is fed to the next roll nip. The uppermost roll andthe lowermost roll are so-called Sym rolls, which have the loadingdevices 3; 31, 32; 31 a, 32 a inside the rolls. With the loading devices31 a, 32 a it is possible to compensate deviations caused by the ownweight of the upper and lower roll 3, but with the help of these it isalso possible to close the roll nips N of the calender and to generatethe desired load to the said roll nips. The loading devices 31 a, 32 aconsist of three shoe element lines, each of which is attached to thefixed axle frame (not shown in the Figure). Each shoe element line hasseveral separate shoe elements, which can be loaded through hydraulicliquid channels leading to them (not shown in the Figures). On top ofthe shoe elements there is a flexible, polymer-coated roll casing 31 b,32 b, which can be rotated on top of the shoe elements. The structure ofsuch a so-called shoe roll is conventional in itself, and it has beendisclosed, for example, in the own patent application of Metso Paper,Inc., so its structure is not described in more detail in thisconnection.

The uppermost roll 3; 31 and the lowermost roll 3; 32 (or the first andlast roll) are attached directly to the calender frame 7 by suitablefastening elements 31 c, 32 c.

Between the uppermost and the lowermost rolls there are fiveintermediate rolls 4, of which the middlemost intermediate roll 4; 43 islikewise attached directly to the calender frame 7 in a similar way asthe uppermost and the lowermost rolls. The outermost intermediate rolls,i.e. the first intermediate roll 4; 41 and the fifth intermediate roll4; 45, seen from the first, i.e. the uppermost roll 3; 31 of the set ofrolls, are heated chill rolls. The outermost intermediate rolls 4; 41,45 are hard-surfaced rolls, which are rotatably pivoted to the bearinghouses 41 a, 45 a from their ends. The intermediate rolls between theoutermost intermediate rolls 41, 45 and the fixedly attachedintermediate roll 43, i.e. the second intermediate roll 4; 42 and thefourth intermediate roll 4; 44 are flexible-surfaced polymer-coatedrolls. The middlemost intermediate roll is fixedly attached to thecalender frame in a similar way as the uppermost and the lowermost roll.The middlemost intermediate roll is a smooth-surfaced metal roll.

The intermediate rolls 41, 42, 44 and 45 are provided with loading arms5 a used as lightening elements 5 (shown more exactly only at the placeof the intermediate roll 4; 41, because the load lightening elements ofthe said intermediate rolls are identical), which are attached to thebearing houses 41 a-45 a of the said intermediate rolls. The loadingarms 5 a are pivotably joined to the calender frame 7 by axiallydirected joints. The loading arms 5 a are provided with lighteningelements, such as piston-cylinder elements 5 b. The lightening elements5 are used for compensating the deflections caused by the own weight ofthe rolls in question in the linear loading profiles transverse to themachine direction of the roll nips. The structure of the loading arms 5a is conventional in itself and, for example, Metso Paper, Inc.'s patentFI 96334 is referred to with regard to their more detailed structure.The diameters and weights of the intermediate rolls 4 have been chosenso that their natural specific deflection is substantially the same.

In FIG. 1, the calendering of the fibre web W is initiated, and the rollnips N are closed. The roll nips N are closed by loading the internalloading devices 31 a, 32 a of the upper and lower roll 3; 31, 32. Theloading devices 31 a, 32 a are loaded by directing hydraulic liquid tothe shoe elements so that the hydraulic liquid forms a lubricatingliquid layer between the shoe elements and the casings of the upper andlower rolls rotating on them. Upon extending, the casing 32 b of thelower roll pushes close the roll nips N; Na2, Nb2 and Nc2 above it.Respectively, the casing 31 b of the upper roll pushes close the rollnips N; Na1, Nb1 and Nc2 below it, as it extends. By loading the shoeelements of the upper and lower roll with a desired force, a linearpressure of about 0-500 kN can be generated to the roll nips N.

FIG. 2 presents the development of the linear load distribution of theroll nips N in the set of rolls 2 as loads are directed to theintermediate rolls 4 on the lower roll 3; 32. For facilitating theobservation it is assumed that the own gravity of the intermediate rollsand the load caused by the auxiliary means related to the intermediaterolls 4; 4; 41, 42, 43 and 44 is completely lightened. The set of rolls2 is similar to the one shown in FIG. 1 so that the intermediate roll 43is fixedly attached to the calender frame. In FIG. 2 it is shown how theadditional load F1 brought to the lowermost roll causes the linear loadF2 in the roll nip N; Nc2 facing the lowermost roll of the fixedlyattached intermediate roll, and the additional load F3 in the roll nipN; Nc1 on the other side of the intermediate roll. The additional loadF1 and the loads F2 and F3 are marked approximately to the middle pointof the lower roll and the roll nips as resultant forces; in fact, theload forces in question are distributed to the length of the whole lowerroll and the roll nips Nc1 and Nc2. The linear load F2 achieved by theadditional load F1 in the roll nip Nc2 between the fixed intermediateroll 32 and the intermediate roll 44 is considerably bigger than thelinear load F3 in the roll nip Nc1 between the fixed intermediate roll43 and the intermediate roll 42, due to the rigid fastening of theintermediate roll 4; 43. The additional load F1 could as well be broughtto the upper roll 31, in which case the additional load would cause alinear load in the roll nip Nc1 between the fixedly attachedintermediate roll 43 and the intermediate roll 42, respectively, whichwould be considerably bigger than the linear load in the roll nip Nc2between the fixed intermediate roll 43 and the intermediate roll 44. Theadditional load can be brought to the lower/upper roll either byinternal loading devices of the said upper and lower rolls 3; 31, 32,with which the deflections usually caused by the gravity of the saidrolls are compensated or, alternatively, the load can be brought to thesaid rolls using an outside force, such as a roll 51 outside the set ofrolls, with which, for example, the lower roll 32 would be pressedtowards the intermediate rolls 4 in the direction of the set of rolls.The direction of the plane of the set of rolls is the same as thedirection of the plane drawn through the central line of the rolls inthe set of rolls.

FIG. 2 also shows the nip load distribution achieved by the additionalload F1 brought to the lower roll 3; 32. The nip load directed to acertain roll nip N is drawn to continue always over the entire roll forillustrating the loads, although the nip pressure influencing in acertain roll nip would not continue in a similar way in the roll itself.From the diagram in the Figure it can be seen that a bigger linear loadcan be achieved to the roll nips between the lower roll 32 and thefixedly attached intermediate roll 43, i.e. the roll nips Na2, Nb2, Nc2by the additional load F1 than to the roll nips Na1, Nb1 and Nc1 locatedafter the fixedly attached intermediate roll 4; 43, as the set of rolls2 is observed from the influencing direction of the force (load) F1.Because the load coming from the first side of the fixedly attachedintermediate roll 4; 43 decreases considerably when transferring fromthe roll nip on the first side of the said intermediate roll to the rollnip on the opposite side of this intermediate roll, it is possible toconsiderably influence the linear load distribution of the roll nipswith the fixed intermediate roll and to then adjust the profiling ofboth sides of the fibre web in a more exact manner than before.

The multi-roll calender shown in FIG. 3A consists of two sets of rolls 2attached to the same frame, with a so-called reverse nip between them.The sets of rolls are identical and for illustrating this, their partsare indicated by the same numbers. Both sets of rolls 2; 21 and 2; 22consist of upper and lower rolls 31, 32 fixedly attached to the frame,and of three intermediate rolls 4, the middlemost 42 intermediate rollof which is fixedly attached to the frame. The outermost intermediaterolls 41 and 43 are polymer-coated elastic rolls, and the intermediateroll 42 attached to the frame is a heated smooth-surfaced chill roll.The outermost intermediate rolls are suspended to the frame from theirbearing houses by loading arms in a similar way as is shown in FIG. 1 inconnection of the intermediate rolls 41, 42, 44 and 45. The upper roll31 and the lower roll 32 are heated smooth-surfaced chill rolls and theyhave internal loading devices for the rolls. The structure of theloading devices is similar to the one shown in FIG. 1, in which thestructure of the upper and lower rolls is described. The path of thefibre web W in the roll nips is shown by arrows with closed ends; forsimplifying the figure, the take-off rolls are not shown in the figure.The last roll 3; 32 of the first set of rolls 2; 21 and the first roll3; 31 of the second set of rolls 2; 22 are smooth-surfaced chill rollsso that a so-called reverse nip is formed to the set of rolls in whichcase it is possible to control the profiling of both sides of the fibreweb with the set of rolls.

The sets of rolls 2 of the multi-roll calender shown in FIG. 3B and themarkings of their parts are similar to those in FIG. 3A, but the sets ofrolls are now arranged to different frames so that the fibre web W isbrought from one set to the other in air.

It is obvious for one skilled in the art that it is possible to realizethe invention in many other ways in addition to the embodimentsdisclosed in the examples above.

Thus, even if one set of rolls in the multi-roll calender (multi-nipcalender) according to the invention preferably has a relatively smallnumber of rolls, in some cases there may be as many as 10-15 rolls ineach set of rolls. In the sets of rolls described above, the uppermostand the lowermost roll are so-called sym rolls, in which pressureelements containing several different pressurizing zones are used forloading the casing of the roll. However, it is fully possible to replacethe above-mentioned internal loading devices of the rolls with otherloading devices known from the state of the art, with which the casingof the lower and/or upper roll can be moved to the direction of theintermediate rolls in a plane defined by the set of rolls.

Likewise, in the examples disclosed above, the sets of rolls are locatedsubstantially in an angle of 90 degrees in relation to the horizontalplane. However, the angle of the plane of the set of rolls in relationto the horizontal plane has no significance as such, and by placing amulti-roll calender or part of its rolls, for example, to the horizontalplane or to some other angle between 0 and 90 degrees, a part of the owngravity of the intermediate rolls or all of it can be leftuncompensated. If the own gravity of the intermediate rolls need not becompensated, equipment for lightening the own weight of the intermediaterolls is not necessarily needed in these intermediate rolls, either.

In the examples disclosed above, the first and last roll in the set ofrolls and the fixedly attached intermediate roll are attached to the(calender) frame. However, it is also entirely possible to attach thesaid rolls to other structures in a paper or cardboard machine or to asupport located on the floor.

Reference numbers of the main parts of the figures Calender 1 Set ofrolls 2 First or last roll 3 Intermediate rolls 4 Lightening element 5Take-off roll 6 Frame 7 Fibre web W Roll nip Na, Nb, NcIn other parts, a numbering mode has been followed, in which the firstnumber of the part informs to which main part the said part isconnected.

1. A multi-nip calender for calendering a fiber web, the calendercomprising: a first set of rolls attached to a first frame, the firstset of rolls having a first roll, a last roll, and a first intermediateroll between the first roll and the last roll, a second intermediateroll between the first intermediate roll and the last roll, and a thirdintermediate roll between the second intermediate roll and the lastroll; wherein the first, the second, and the third intermediate rollslack internal devices for loading or moving the rolls, and wherein thesecond intermediate roll being rotatable about an axis which is fixedwith respect to the frame, and the first and third intermediate rollsare mounted for vertical motion on the frame; wherein the first roll andthe last roll are polymer-coated rolls each having a casing which ismovable with respect to a portion fixed to the first frame, and eachhaving internal loading devices with which the casing is movable towardthe second intermediate roll; and a plurality of roll nips is definedbetween the rolls of the first set of rolls, such that the rolls fromthe first roll to the last roll alternate between polymer-coated rollsand metal rolls, and the roll nips in the set of rolls are closed bymoving the casing of the first roll with its internal loading devices ina first direction parallel to a plane extending through the set of rollstoward the second intermediate roll, and the roll nips in the set ofrolls are closed by moving the casing of the last roll with its internalloading devices in a second direction opposite the first direction andparallel to the plane extending through the set of rolls, towards thesecond intermediate roll.
 2. The multi-nip calender of claim 1 furthercomprising at least one additional intermediate roll, said at least oneadditional intermediate roll lacking internal loading devices forloading or moving the rolls and having an axis which is movable withrespect to the frame, said at least one additional intermediate rollbeing positioned between the second intermediate roll and the first rollor between the second intermediate roll and the last roll.
 3. Themulti-nip calender of claim 2, in which said at least one intermediateroll, and the first intermediate roll and third intermediate roll hasequipment for lightening its weight.
 4. The multi-nip calender of claim2 in which a linear load distribution of the roll nips in the set ofrolls is controlled by an additional load brought to the first and/orlast roll in the set of rolls, wherein: the additional load of the firstroll in the set of rolls is used for influencing the linear loaddistribution of the roll nips between the second intermediate roll andthe last roll to a substantially lesser extent than the linear loaddistribution of the roll nips between the second intermediate roll andthe first roll; and the additional load of the last roll in the set ofrolls is used for influencing the linear load distribution of the rollnips between the second intermediate roll and the first roll to asubstantially lesser extent than the linear load distribution of theroll nips between the second intermediate roll and the last roll.
 5. Themulti-nip calender of claim 4 wherein the additional load is brought tothe first and/or last roll in the set of rolls using a loading elementoutside said roll.
 6. The multi-nip calender of claim 5 wherein theloading element is a roll.
 7. The multi-nip calender of claim 4 whereinthe additional load is brought to the first and/or last roll in the setof rolls using the internal loading devices of said first and/or lastroll.
 8. The multi-nip calender of claim 1, wherein the first rolland/or the last roll are shoe rolls, in which the internal loadingdevices of the first roll and/or the last roll comprise one or severalshoe elements located under the casing of the roll, at the roll nip,which one or several shoe elements can be loaded with liquid so that thecasing of the first roll and/or the last roll moves in relation to thesecond intermediate roll in the set of rolls.
 9. The multi-nip calenderof claim 8, wherein the first roll and/or the last roll has two orseveral shoe elements for moving the casing of the first roll and/or thelast roll and for profiling the fiber web.
 10. A multi-nip calender forcalendering a fiber web, the calender comprising: a frame; a first rollwhich is a polymer-coated roll having a casing which is movable withrespect to a portion fixed to the frame, and the first roll having aninternal loading devices with which the casing is movable toward a firstintermediate roll; a last roll which is a polymer-coated roll having acasing which is movable with respect to a portion fixed to the frame,the last roll having internal loading devices with which the casing ismovable toward the first intermediate roll, wherein the firstintermediate roll is positioned between the first roll and the lastroll; a second intermediate roll having a casing and positioned on theframe between the first intermediate roll and the last roll; a thirdintermediate roll positioned on the frame between the secondintermediate roll and the last roll; a fourth intermediate roll having acasing and positioned on the frame between the third intermediate rolland the last roll; a fifth intermediate roll positioned on the framebetween the fourth intermediate roll and the last roll; wherein thefirst intermediate roll lacks an internal loading device for loading ormoving the first intermediate roll; wherein the second intermediate rolllacks internal loading devices for loading or moving the secondintermediate roll; wherein the third intermediate roll lacks internalloading devices for loading or moving the third intermediate roll;wherein the fourth intermediate roll lacks internal loading devices forloading or moving the fourth intermediate roll; wherein the fifthintermediate roll lacks internal loading devices for loading or movingthe fifth intermediate roll; and wherein the third intermediate roll isrigidly mounted to the frame, and the first, second, fourth, and fifthintermediate rolls each have an axis which is movable with respect tothe frame so that the first, second, fourth, and fifth intermediaterolls are mounted for vertical motion on the frame; a plurality of rollnips defined between the first roll, first, second, third, fourth, andfifth intermediate rolls and the last roll, such that the rolls from thefirst roll to the last roll alternate between polymer-coated rolls andmetal rolls, and that roll nips between the first roll and the thirdintermediate roll are closeable by moving the casing of the first rollwith its internal loading devices in a first direction towards the thirdintermediate roll, and so that roll nips between the last roll and thethird intermediate roll are closeable by moving the casing of the lastroll with its internal loading devices in a second direction oppositethe first direction towards the third intermediate roll.
 11. Themulti-nip calender of claim 10 in which a linear load distribution ofthe roll nips in the multi-nip calender is controlled by an additionalload brought to the first and/or last roll in the set of rolls, wherein:the additional load of the first roll in the set of rolls is used forinfluencing the liner load distribution of the roll nips between thethird intermediate roll and the last roll to a substantially lesserextent than the linear load distribution of the roll nips between thethird intermediate roll and the first roll; and the additional load ofthe last roll in the set of rolls is used for influencing the linearload distribution of the roll nips between the third intermediate rolland the first roll to a substantially lesser extent than the linear loaddistribution of the roll nips between the third intermediate roll andthe last roll.
 12. The multi-nip calender of claim 11 wherein theadditional load is brought to the first and/or last roll in the set ofrolls using a loading element outside said roll.
 13. The multi-nipcalender of claim 12 wherein the loading element is a roll.
 14. Themulti-nip calender of claim 11 wherein the additional load is brought tothe first and/or last roll in the set of rolls using the internalloading devices of said first and/or last roll.